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Climate Change Challenges MOOC (2)
This week started with Professor Tim Lenton taking a look into deep time and the early state of planet earth.
In the beginning, well pretty early on anyway, the sun was much cooler than it is today, it was 25% -30% less bright so one would imagine the earth’s temperature would be much cooler but in fact it was actually warmer than today. This was due to a rather thicker blanket of greenhouse gasses, later some of these gases were slowly removed over time by the action of the carbon cycle.

(Professor Tim doesn’t like ‘greenhouse’ terminology but the rest of the world still uses it so it has become something of a lingua franca.)

The carbon cycle extracts carbon from the atmosphere basically by dissolving CO2 in the raindrops and forming a weak acid. This then weathers the rocks and that reaction ends up creating carbonate ions, which, in turn, are washed into the oceans and waterways. The next change is a bit murky, somewhere along the way the carbonate ions get snaffled up, often it seems by calcium, and then quickly converted into seashells or similar. Eventually the carbon becomes part of the lithosphere as it morphs into carbonate rocks, something akin to the famous white cliffs of Dover perhaps. The carbon cycle is a negative feedback and as such it tends to maintain an existing state. As the sun’s radiation increased and the earth warmed the reaction speed increased, removing CO2 and cooling the planet.

But negative “put it right” feedbacks do not always win. Back in deep time again (2.2 billion & 700million years back) the earth froze over. The trigger is not clear – it may have been something to do with the continents forming. In any event a positive “make it worse” feedback problem developed. The poles froze, the ice reflected more heat, the planet cooled further and froze and cooled some more and once the ice reached the tropics well that was it, a snowball.http://www.bbc.co.uk/nature/ancient_earth/Snowball_Earth But not forever because – well it isn’t frozen now –and the earth still had at least one get-out-of-gaol-free card left. Volcanoes. Again this took an awful long time but the volcanoes slowly put lots of CO2 and other gases back into the atmosphere, which started the world warming again and as the ice melted under the warming blanket of gasses so the reflectivity of the globe reduced and a little more warmth got through, ice melted, water evaporated, warming increased and we were back in business.

There are several mechanisms that create natural climate variability. They are mainly long term changes triggered by changes to the earth’s orbit (Eccentricity), the tilt of its axis varying (Obliquity) and the wobble of the axis (Precession). These changes are regular and predictable albeit on long time scales. They are called Milankovitch Cycles.
Volcanoes and solar activity also influence the climate and they are not regular or predictable but we can pinpoint those events using tree rings and/or ice cores for proxy dating information and compare the results against historical records of climate events such as the mediaeval warm period. The signature of the Mt Pinatubo volcanic eruption in 1991 is visible as a 2 or 3yr dip in global temperatures but in general global temperatures are rising and CO2 emissions are increasing at a much faster rate than has happened with previous natural climate variation.
Studies of the Ice Ages go back quite a long way and there is now a recognized discipline, Paleoclimatology, thanks to Svente Arrhenius, who in 1895 suggested that a reduction in CO2 concentration in the atmosphere could account for the drop in temperature during the ice age. He was also the first person to investigate the effect that doubling atmospheric carbon dioxide would have on the global climate.
Comparing historical data with the temperature rise over the last 100 or 150 years it seems there is a mismatch, first there is an of excess CO2 in the atmosphere but also the changes are happening much faster than would be expected. http://earthobservatory.nasa.gov/Features/GlobalWarming/page3.php
The only way the models can reflect what actually happened is if the CO2 produced by the industrial revolution is included in the equation.

How right they were!

This is not surprising really because burning coal and oil is really releasing fossilized sunlight back into the atmosphere and the extra heat must go somewhere.

Volcanic eruptions produce dust and aerosols that act to provide short term cooling, however seems unclear as to whether there is any long term warming effect from the gasses emitted and also the effect of different aerosols and the interactions between them is unclear.

Most aerosols are of natural origin and key groups include sea salt, nitrates, sulfates, organic carbon, black carbon & mineral dust and they often clump together and form complex mixes. Sea salt, dust and volcanic ash are common types of aerosol, only about 10% of aerosols are of anthropogenic origin.

Different aerosols reflect or absorb sunlight depending on their make up. Large volcanic eruptions can cool the earth for a year or more while sulfate aerosols remain in the atmosphere, black carbon deposited on ice or snow can contribute to global warming by altering the albedo (reflectivity) of the planet. It is a complex area and potential impacts are not fully understood. It certainly makes me worry about potential Geoengineering solutions to climate change….

On January 17th 2015 NASA reportedly announced that 2014 was the world’s hottest year ever recorded and that this formed part of a continuing trend. It was also noted atmospheric CO2 levels are continuing, intermittently, to reach 400ppm. We are currently on a trajectory widely agreed to be heading for a temperature increase of around 5degC.
So is it possible that the strength of market forces could change the future, moving us from a pathway heading into a climate change disaster to one that instead leads us through the minefield to a safe haven? There are people who think this is a reasonable assumption and while I can understand the reasoning I must admit to being rather more pessimistic.

There are certainly many lights shining on a multitude of hills. The Chinese are moving quickly to reduce the use of coal and to ensure they return the atmosphere in their cities to pure clean breathable air and they have done some remarkable work rehabilitating degraded land as in the Loess valley, the USA is promising to move swiftly to control its emissions and even if its federal government fails to act there are several states which together are moving to take control and reduce greenhouse emissions. There are reports that the German State of Schleswig-Holstein has achieved 100% renewable power in 2014 and intends to triple that total. It may not be enough to change everything but it will be a serious commitment and as such could lead the world into a renewable future.
Yet in spite of these hopeful indicators it seems that we are already into planetary overshoot with resource use and pollution exceeding the natural ability of the world to absorb the waste or maintain our economy on a sustainable basis. The myopia of the market is reflected in pressure from corporate and government interests to open more coalmines, to extract oil from deep undersea sources, to increase coal seam gas extraction. At the same time the science estimates that to have a 50-50 chance of a reasonable climate future, a third of the world’s oil reserves, half the gas reserves and more than 80percent of the coal reserves cannot be used.

To help us all to change on 13th & 14th February 350.org will run a worldwide ‘divestment day’ to help the world to break up with fossil fuels, so check where your superfund invests, change your bank, re-assess your share portfolio if you have one. Another straw in the wind that perhaps suggests impending change.

There are serious questions to be answered about food production as well. Not only does our current monoculture agribusiness approach make quite large contributions to emissions it is also likely to be disrupted by climate disasters with floods or droughts hitting major food producing areas in the USA, or Australia. Some analysts have linked the Arab Spring to food shortages, triggered by drought and the associated reduced harvest size and high wheat prices. Other factors that might drive wheat prices higher are the use of agricultural land to produce ethanol for transport and fodder for feedlot cattle. Of course we should not forget the anticipated world population increase. The UN Food and Agriculture Association Asia-Pacific suggests that to avoid political turmoil, social unrest and civil war the world needs to increase food production by 60% by 2050

All this needs to be done without further stressing our natural ecosystems
Paul Ehrlich & Anne Ehrlich in a Simplicity Institute paper “Can a Collapse of Civilization be Avoided?” published by the Royal Society in 2013 pinpoints the likely triggers for collapse and looks for major cultural change for the hope of avoiding disaster:Abstract : Environmental problems have contributed to numerous collapses of civilizations in the past. Now, for the first time, a global collapse appears likely. Overpopulation, overconsumption by the rich and poor choices of technologies are major drivers; dramatic cultural change provides the main hope of averting calamity.

Such a cultural change could be based on an underlying human tendency to cooperate rather than to compete. Can I hear ribald laughter in the gallery at such an unreasonable suggestion? Quite possibly, however a paper in published in Nature seems to support the idea… and also that cooperative behavior cascades to extend its influence through a population (Fowler & Christakis)

Then there are also suggestions that the capacity and perhaps a need to cooperate was an effective driver of the success story for early mankind. And surely markets were a part of that cooperation, markets that traded obsidian across hundreds of kilometers at a time when foot traffic reigned supreme. And another gem that paleoanthropology has thrown up is the idea that past climate change was also a trigger for the rapid evolution that saw homo sapiens out compete its rivals. Perhaps we are set for a great leap forward into a sustainable future and not a blind stumble that lands us in the trash can. A nice thought to end on perhaps.

The eighth week of the “Climate Change, Challenges and Solutions” MOOC has come to a close and for me it has been a really worthwhile experience. In the final week we approached the question “Is the future of the climate still in our hands?” Very clearly it is within our reach to either maintain the current path of high, and growing, CO2 emissions or to change our direction.
If we choose not to change the way that we create power by burning fossil fuels, if we persist with a culture based on a dig it up, use it and throw it out philosophy then our outlook is very poor indeed. Travelling that path, by the year 2100, atmospheric CO2 will have reached levels that exceed 1000ppm and will possibly be as high as 1500ppm. This will mean that the average world temperatures will perhaps be 6degC warmer than today. It would take one million years for the earth’s natural weathering systems to remove this amount of CO2 from the atmosphere.

CO2 reached 400ppm late last year. It hasn’t been that high for 650,000 years

Travelling this path will mean more violent weather events, more floods, heat waves, wildfires and droughts. I doubt that our current flawed economic and social system will survive these shocks but if it did survive we would then be facing a slow but inevitable rise in sea level as the Greenland and Antarctic Ice Sheets melt, an unstoppable increase that will raise sea levels by up to 70 meters. CO2 persists in the atmosphere for a long long time and this is one reason why we know that the timelines for reducing our emissions are critical.

An info graphic put out by the Climate Council

There is an alternative.
The current trajectory will see us locked into rising emissions, higher temperatures and long term devastation but we can change this outcome and still make a measured transition to a new way of living. If we base our future on fairness, sustainability and equity we could actually use this crisis to embrace change. Science has given us the tools and the all the information that we need to move to a sustainable and resilient world, only vested interests and politicians stand in the way. We can change the politicians and now even some of the vested interests are beginning to recognise that they too need a sustainable world order.
Clearly we must price pollution at a rate that is proportional to the damage caused to the ecosystem, the economy, the society and the individual. We probably need to support sunrise industries that will help to cut pollution, industries like wind and solar power and of course we must stop burning fossil fuels. These critical first steps need to be taken in the near future so that we can start to reduce our emissions during this decade, meet or preferably exceed the undertaking we made to reduce our emissions.
Once we have started along this path we can turn our minds to finding effective ways to draw down atmospheric CO2. Maybe carbon capture and storage will finally become a viable option, although I doubt if it will ever be a cheap one. Leaving forests standing is a very good way of locking up carbon for hundreds of years and the amount of carbon stored continues to increase throughout the life of the trees. Tackling our throw away society and demanding that industries find a use for all their waste products so that instead of a linear system of constant through-put we have a circular system that minimises new resource input and virtually eliminates waste.
Bearing in mind that true sustainability also requires equity to be successful, wealthy nations like ours should be prepared to help disadvantaged nations to move directly to a clean renewable energy supply skipping the dirty coal fired power that destroys the climate. They may be more successful than we are, because the large vested interests that are keeping fossil fuels alive and preventing the development of distributed power are not in such a powerful position as they are here.

We are now into week seven of “Climate Change – Challenges and Solutions” and this week we examined the possibilities and options for mitigation and adaptation. On the mitigation front, having seen the pitfalls of geoengineering solutions looming large on the horizon we turned our attention to the built environment, which is responsible for a high percentage of our emissions and also to renewable energy which can give us a good start in reducing them.
I have some background in this area so I was aware of the huge strides that have been made in the design of energy efficient buildings, but of course most of the housing stock and many commercial buildings pre-date sustainable design. Much of our housing is built close to the ocean and only a few metres above sea level, will it survive repeated major flooding as sea level rise and storm surges impact on the coast? Will it be able to deal with the rising temperatures that are anticipated?
We looked at the impact of heat islands in built up environments and the increased number of deaths that are related to heat waves. This course is being run out of the UK so the question of wild fire was not even considered but flooding was certainly discussed.
We were asked to review the built environment in our own locality. This small house, still under construction, will be adequately insulated, it faces due North (correct orientation for the southern hemisphere) and has deep eaves. This will allow winter sunlight into the house and being small in size it will be easy to heat in winter. It has one large west facing window which could be a problem in summer but an external blind will take care of that. The eaves will shade the glass in summer and there is cross ventilation to assist in cooling. I think there will be a degree of climate resilience built into the house.

A 1980s house

This architect designed house is an example of a house built before climate change became an issue. It faces almost due west to take advantage of the views over the lake but because it has a very wide covered deck it wouldn’t have too much of a problem until fairly late in the day and it would be easy to drop canvas blinds along the deck. Being built on a slope it has some rooms under the living area which will remain cooler and give some resilience as the climate warms.
I think that where site conditions have been properly considered during the design stage the old housing stock will have a level of resilience but probably much of the developer led housing that has been built in the last twenty or so years will be pretty much a write off eventually.
And to give an idea of the location a map because I simply couldn’t cope with the suggested geo tags. The star is the existing house and the teardrop is the site of the new build that is underway.
The second half of the week was devoted to renewable energy. It is clear that this is the “get out of gaol (almost) free” card. The UK has about 11% renewable energy at the moment and are looking to reach 30% by 2020. There are some active anti wind organisations and they are also going to build a new nuclear power station. They seem to think that nuclear is cheap (ha ha!) and renewables are expensive which is crazy.
Denmark on the other hand has 30% renewable energy now and is expecting to have 50% by 2020 and 100% renewables by 2035. Go Denmark! I think it has been made quite clear that one of the biggest obstacles to dealing with climate change is the entrenched opposition from fossil fuel protagonists. We can’t afford to let them win. It is also interesting to note that the gulf states are putting in solar power in order that they can get the most out of the last of their oil reserves by selling them to people like us who refuse to recognise the reality we are facing.
Next week we are looking ahead to the medium and longer term effects of climate change. I approach it with some trepidation.

This week at the Exeter MOOC that looks at ‘Climate Change’ and its complexity we first looked at the impact of global warming on ice sheets, glaciers and sea ice. Understanding how the warming earth disturbs, amplifies or changes the natural processes of glacier calving and ice sheet melting is really critical. We are depending on this when we estimate how fast and how high sea levels will rise in the coming years. If all the ice sheets melt the sea rise would be 65m but of course that will take quite a long time. Even so with many people living at elevations little more the a meter or two above sea level things will get a bit uncomfortable. Understanding how the glaciers behave will also be critical for understanding the fresh water cycles I think, countries in Asia with high populations and huge rivers may well be put under threat because many of the Asian rivers are fed by Himalayan glacial meltwater. We were given web addresses that showed photographic evidence of a massive decrease in the size of the Himalayan glaciers. There were panoramic photographs taken by the British in the 1920s and again in recent years the glaciers have been photographed from the same positions. Side by side (or actually one above the other) they make a sobering comment on the future.
Glacierworks:Everest is definitely worth exploring.http://explore.glacierworks.org/en#glaciers

Well that was the first half of the week and the second half was just as challenging because we now started to look at the effects of CO2 being absorbed into the ocean. This is quite a complex thing to get your head around as well.
It involves a bit of chemistry but not too much because I could follow most of it (I think) and chemistry was never my strong point. It works like this … the CO2 dissolves in the sea water and forms a weak acid which then dissociates into free H (hydrogen) ions and carbonates. The carbonates would normally be available to be combined with calcium and used to form the shells of the tiny sea creatures at the bottom of the food chain, but if the environment is made more acidic by an excessive amount of free hydrogen ions the process starts to fail. The acidity in the ocean starts to damage the shells of the tiny phytoplankton and pteropods that form the basis of the ocean food chain and it also makes it much harder for their shells to form. I think of this as being similar to plant sensitivity to soil ph, for example many vegetables can only access nutrients within a certain ph range and we can test our soils and adjust them if necessary. Pity we can’t do that with the ocean.
This ocean acidification is one big long term threat to the ocean food chain and all the people that depend on reefs, estuaries, lakes and inlets, fishing and aquaculture for much of their protein, sport and relaxation. We all need to worry.

Fishing in a lake near Bermagui

I also followed up on some work I had come across by a paleo-climate scientist Andrew Glikson, Visiting Fellow at ANU School of Archeology and Anthropology. One thing I found was information on the relationship between the high levels of CO2, increased sea levels and the four large mass extinction events that have occurred in the history of the earth. It seems to me if rising CO2 on a geological timescale (taking aeons to build up) can cause mass extinctions then there is very little hope that the same will not happen with the current rate of CO2 increase in the atmosphere. We urgently need to stop producing the stuff as we power our homes. Old King Coal has got to go.
Andrew Glikson mentions something called “serpentine sequestration” but all I could find on that was a rather heavy paper from Bath Uni which talks of capturing CO2 and reusing some of it in high tech manufacturing of polymers etc. but the paper recognises that the big problems are cost and finding enough space to sequester the CO2 once it has been captured. It seems to be another attempt at using the mind set that created the problem to attempt to solve it.
On the other hand he also speaks of using soil carbon and a world wide effort to sequester carbon in forests and agricultural projects. And of course we must cut our emissions to Zero ASAP.

This week the University of Exeter Future-Learn getting-bigger-all-the-time MOOC took a long hard look at models (no NOT Naomi Campbell) I am talking about massive super computer analysis of weather and climate and all that stuff. When the models are first constructed they are run using known historical data going back about 150 years and the climate outcomes they produce can then be verified against the historical records. This gives a level of confidence in projections plotted for future outcomes. This is also how the fingerprint of anthropogenic warming was identified because the models run from 1970 onwards will not match the climate records for that period if the CO2 that results from burning fossil fuels is excluded from the data set.

Modelling a future outcome
Of course we don’t know the future levels of CO2 or population or uptake of renewable energy so things like this become the variables and the model then indicates the likely result for any one particular set of circumstances. What can (or should) be articulated clearly is that the outcome for the future is firmly our hands and that increasing CO2 emissions must be curbed. It seems that we have already pumped enough CO2 into the atmosphere to make sure that sooner or later the temperature rise will equal or exceed 2degC and dangerous climate change will catch up with us.

Geoengineering
The next thing under discussion was the vexed subject of geoengineering and rather than try to précis such a complex issue I am including a youtube link – it lasts about 25mins and does cover a few other things as well. Things like clouds, did you know that those light whispy cirrus clouds that once were seen as heralding a fine day are villains in the climate scenario and likely to increase warming while threatening low clouds have a cooling influence? In someways it seems a bit back to front.
Carbon Capture and Storage, that old furphy is still being rolled out but high cost and the doubtful prospect of finding enough suitable storage seems likely to keep it as a pipe dream. Most of the “reflect the sunlight” schemes proposed would seem to have serious problems and while vegetation and trees are briefly mentioned there was no discussion about the storage potential of forests in general or old growth forests in particular. There was mention of increasing ocean storage potential but there are difficulties in making it effective. Check out the video below for more details.

Next week we will be looking at climate change impacts on the ice and the oceans. As previously there will be visiting specialists on hand to make everything clear. We certainly are getting the info straight from the horses mouth (for want of a better analogy)